Leaking oxygen tank led to Mich. pilot's fatal crash, NTSB finds

Gary Miles
The Detroit News
The airplane flown by Gaylord Dr. Michael Moir, Mooney N370MM, was recovered from a depth of about 45 feet in the Atlantic Ocean.

A leaking oxygen tank probably led to a Gaylord pilot's fatal 2015 crash into the Atlantic Ocean, the NTSB has found.

Gaylord dentist Michael Moir, 68, died on Sept. 10, 2015, after losing contact with air traffic controllers for more than two hours from his home airport en route to an airplane safety conference in Atlantic City.

The loss of radio contact prompted harried attempts to reach him by controllers and pilots across Ontario and the eastern United States, according to radio transcripts, culminating with the dispatch of two F-16 fighters.

The NTSB found the hose that connected the oxygen tank to Moir’s oxygen mask, used for flying at altitudes above 10,000 feet, was loose. It went undetected in a June 2015 annual inspection of the plane and probably allowed Moir’s tank to drain, rendering him incapacitated, said the report issued earlier this week.

“Although the pilot was found wearing an oxygen mask, given the high altitude the airplane was at for the duration of the flight, the pilot’s failure to respond to controller contact, and evidence indicating that he would have had reduced availability of supplemental oxygen, it is likely that the pilot became incapacitated due to hypoxia,” the NTSB found.

Hypoxia is a debilitating loss of oxygen that slows motor skills and can cause confusion and a loss of consciousness.

Dr. Michael Moir.

“The airplane’s continued flight at 25,000 (feet above sea level) and its descent profile were consistent with the airplane operating under autopilot control and then descending to water impact due to fuel starvation,” the report said. The plane likely had more fuel, but required the pilot to switch between two tanks, one in each wing, a task Moir would have been unable to complete.

Dr. Gregory Pinnell, founder and flight surgeon for Saginaw-based Air Docs, said pilots have very few minutes of useful consciousness without supplemental oxygen at such a high altitude, although they may not lose consciousness altogether.

“That’s a commonly misunderstood thing about the time of useful consciousness,” he said. “It doesn’t necessarily mean that you’re not awake, but you’re functionally incapacitated.”

Efforts to reach Moir were complicated by at least one report that he had responded to a controller at Allentown, Pa. It was unclear, however, whether the controller heard Moir or one of many controllers or pilots trying to reach him as he flew over Ontario, Pennsylvania and New Jersey.

Hypoxia continues to be a dogged killer of pilots at high altitudes, partially because its effects are varied. One of the most famous US crashes resulting from loss of oxygen involved the death of professional golfer Payne Stewart in 1999.

"They say hypoxia fatalities are a serial killer and they're absolutely right, we never seem to get away from them," Pinnell said. "In the general aviation, every once in a while they seem to happen."

Moir was born in Detroit in 1946 and left behind a wife, Jean, and son, Keith.

His crash, at 2:48 p.m. on Sept. 10, came as pilots from around the nation attended a conference for Mooney airplanes, the type of single-engine plane Moir was flying.